Heyday app is the anti-Facebook for the iPhone

Heyday will create a virtual journal including all of the places you have visited and the photos you have taken.

These days, people can't eat a meal or pet a cat without sharing it on the Internet. But what if people want to relive their digital lives in private?

That is where a new iOS app called Heyday comes in. It combs through your past photos and automatically logs your location data to create a personalized journal — all for your eyes only.

It's kind of like Facebook Timeline, except that everything is private by default. Heyday co-founder and CEO Siqi Chen told NBC News that he was inspired after talking to users of both Facebook and Foursquare, a social media app that lets you share your location with people you know.

"About half of the Foursquare users we talked to had accounts with no friends," he said. "And with Facebook , users were tired of people over-sharing with things like baby and vacation photos. There weren't that many products that helped people remember their lives for themselves."

Creating your own journal is pretty easy. After downloading the app from iTunes, I had my own virtual scrapbook up in around five minutes. After letting Heyday access my photos and location info, I didn't have to do anything — I just waited for the app to automatically assemble colorful collages filled with snapshots that I had taken over the life of my phone. Heyday pretty much does all of the work, choosing photos with faces or lots of color in them, and leaving out duplicates and pictures that are too dark.

Then, you are free to edit individual photos and albums, add labels, privately tag your friends and jazz up pictures with 18 different filters. And, yes, you can share them on Facebook or Twitter if you feel like it.

Everything is stored locally on your phone, which helps the journals scroll quickly and smoothly. (Information is backed up on the company's servers, an option that can be switched off from within the app).

Chen, speaking from his office in San Francisco, sounded somewhat existential in explaining why Hey, Inc. started work on the app 18 months ago.

"It fulfills an itch that users didn't know they had until Heyday," he said. "If you forget what you did a year ago, you basically forget that you forgot, so that time that you lived disappears. We think that's really sad."

Keith Wagstaff writes about technology for NBC News. He previously covered technology for TIME's Techland and wrote about politics as a staff writer at TheWeek.com. You can follow him on Twitter at@kwagstaff and reach him by email at: Keith.Wagstaff@nbcuni.com